A film magazine for use in photography usually has structure shown in FIG. 3.
In FIG. 3, 50 is a film magazine, 51 and 52 each represent a cap portion, 53 is a lip portion that is a film outlet, and 54 is a film.
In a film magazine having such a structure, a blank sheet that is sized to predetermined dimensions is formed to be boat-shaped, then a velvet ribbon 55 is pasted thereon as a light-shielding member, and then the blank sheet is rounded to be film magazine 50 shown in FIG. 3. After that, the rounded blank sheet is covered, at its both ends, with cap portions 51 and 52 for manufacturing. Incidentally, the velvet ribbon is usually blackened so that it may have a light-shielding function. In addition to the light-shielding function, the velvet ribbon is required to have softness so that it does not damage a film when the film is taken out or is rewound. Therefore, the velvet ribbon is made in a way wherein a soft pile yarn such as viscose acetate yarn or nylon yarn is crimpled and woven into a base cloth.
In a film magazine forming apparatus that rounds boat-shaped blank sheet 56 (FIG. 4) that is pasted with velvet ribbon 55, on the other hand, blank sheet 56 fed from the previous step on a one by one basis is fed by transport member 57 with a printed side of the blank sheet facing downward (velvet ribbon 55 facing upward and a printed side being kept in contact with a transport member slidingly) as shown in FIG. 4, and then is formed by the film magazine forming apparatus to be almost cylindrical as shown in FIGS. 5(a), 5(b) and 5(c).
Incidentally, in FIGS. 5(a),5(b) and 5(c), the numeral 58 represents a supporting member for blank sheet 56, the numeral 59 represents a side mould for moulding use provided thereon with a concave portion 60 which is a core mould. Core mould 60 is positioned above side mould for moulding use 59 and supporting member 58, and as shown in FIGS. 5(b)-(c) to the blank sheet 56 is formed almost into a cylindrical shape by core mould 60 and by side mould for moulding use 59.
However, the film magazine forming apparatus having the structure stated above is faulty for the following reasons.
(1) Since the blank sheet 56 is transported, with its printed side facing downward, by the transport member 57 (velvet ribbon 55 facing upward and a printed side being kept in contact with a transport member slidingly), the printed side is rubbed while it is transported, resulting in damage thereon and the consequent reduction of commodity value of a film magazine.
(2)Since the blank sheet 56 is formed on a long fulcrum between point O where the blank sheet is sandwiched by supporting member 58 and core mould 60 and point P where the blank sheet touches the upper point of a concave portion of side mould for moulding use 59, bent portion 61 shown in FIG. 5 (b) tends to be caused to form respectfully in the area between point P and point O and the permanent set of this bent portion 61 stays even after the blank sheet is formed as shown in FIG. 5 (c), resulting in an imperfect cylindrical shape on a final product and the consequent reduction of commodity value of a film magazine.
(3) Further, since film magazine 50 formed into a cylindrical shape is fed to the next step by feeding claw 62 as shown in FIG. 6, jamming tends to take place while the film magazine is fed, and transport trouble tends to be caused on feeding claw 62 located on the side of film magazine 50 by unevenness of pile thickness on velvet ribbon 55.
(4) Further, since the film outlet on the cylindrically-shaped film magazine 50 is located on the top of core mould 60 as shown in FIG. 6, its attitude is unstable and feeding claw 62 tends to come off, resulting in transport trouble and crashing of the magazine.
(5) Since the velvet ribbon 55 provided at the film outlet on the cylindrically-formed film magazine 50 is rubbed while the film magazine is transported, pile tend to come off and stick on the internal surface of film magazine 50, resulting in possible contamination of a film loaded in a film magazine and the consequent reduction of photographic characteristics of the film.